It is known that wooden frames can be equipped [encased in part] with weather resistant surfaces by running the wooden components through a special extruder which places a weather resistant rigid polyvinylchloride shell on selected surfaces of the wood. An example of the latter is Andersen 400 series patio door which has an outer polyvinylchloride skin which is bonded to the exterior faces of the wooden components in an extruder of a special design which allows a wooden component to pass through the extruder when the skin or shell is applied to selected surfaces of the wooden component. With this described process, sometimes the shell or skin does not adhere well to the wood or delaminates later. Moreover considerable milling of the wooden components in such frames is required, increasing the overall costs. Also problems result from insect or rot infestation of the wood and/or warpage when the frame is in place in use since the vinyl shell or skin does not increase stability of the wood component or provide complete encasement.
In contrast the novel patio door frame of this invention is made of frame members which are a fully extruded members, employing multiple extruders. As a result of the novel extrusion process each frame member has a constant cross section, like pipe, rod, tube, etc. but with several integral components, including a rigid plastic shell for the exterior or weather faces of the frame member, a core element of polyvinylchloride/wood flour foam with channels formed therein for door components and integral flexible plastic sealing strips incorporated in the channels. Three or more extruders are employed in fabricating the novel frame member and coordinated to achieve a single extruded product.